As far as your GTP to put it in such a large cage it WILL stress it out.
not counting there is NO way u are keeping the humidity levels up where they need to be in that large of a cage and if u were, how sad is that for the ball python. U got an African animal in with a Australian animal they are 2 different levels all together with heat and humidity ect.
Substrates for my balls are aspen and the substrate for my GTP is cypress mulch.
Not only should u not cage the animals together.
But I feel from the mild description of the cage it might be improper for both animals.
Bigger is not always better. Just because the animal eats doesn’t mean it has proper care.
Ideal caging for Gtp's is a tub while it’s a neo until its approx. a year old, once the animal is a year old u can move it to a display cage. The more plants and greenery in the cage can help make the animal feel secure.
I am not trying to seem harsh I personally just want what’s best for the animals.
If u post pictures of the housing this may help.
Wishing u well